1. Field of the Invention
The present invention relates to a golf ball having a multilayer construction of at least three layers which includes a core, an intermediate layer and a cover. More particularly, the invention relates to a golf ball which has good rebound characteristics and provides an excellent travel distance, durability and xe2x80x9cfeelxe2x80x9d upon impact with a golf club.
2. Prior Art
In recent years, solid golf balls, with their good flight performance, have consistently won greater general approval than conventional thread-wound golf balls.
Solid golf ball constructions include two-piece balls made of a solid, high-resilience, rubber core enclosed within a relatively thin resin cover, and multi-piece balls having a core, a cover, and also an intermediate layer therebetween whose properties differ somewhat from those of the cover.
As already noted, because of their good flight performance (i.e., long travel distance), solid golf balls of these types are widely favored mainly by amateur golfers. Yet, there remains a desire among golfers for even better flight performance.
It is therefore an object of the present invention to provide a golf ball having a multilayer construction of three or more layers that has satisfactory rebound characteristics and is endowed with improved distance without diminishing the durability and feel that are so important to average golfers.
Accordingly, the invention provides a golf ball comprising a rubbery elastic core having a center and a radially outer surface, a cover having a plurality of dimples on the surface thereof, and at least one intermediate layer situated between the core and the cover. The intermediate layer is composed of a resin material which is softer than the cover. The elastic core has a hardness which gradually increases radially outward from the center to the surface thereof, and a difference in JIS-C hardness of at least 21 between the center and the surface.
Preferably, the JIS-C hardness at the center of the core is 40 to 60, and the JIS-C hardness at the surface of the core is 70 to 90. The core typically undergoes a deformation of 3.5 to 6.0 mm when the load applied thereto is increased from an initial load of 98 N (10 kgf) to a final load of 1,275 N (130 kgf). The intermediate layer is preferably formed of an intermediate layer material containing at least 30% by weight of a thermoplastic polyester elastomer.